It is a common situation to have a large number of people or institutions that require access to an area secured with a lock. One solution to this problem of multiple user access is to provide each user with a key to the lock. However, this presents logistic problems in distribution and control of access authorization. With this solution, users that need access to many sites can be required to carry and organize an unmanageable number or keys. In many cases, users prefer to each maintain their own system of locks having the same key (e.g., master key) to access many sites. The default solution to provide multiple lock access to gated areas appears to be by securing the gate with a chain and several padlocks linked to each other in a sequential “daisy chain” loop. However, besides being unsightly, this system often leads to a lock out of other users when one user directly locks the chain leaving the other locks out of the loop. Many other solutions to the multiple lock problem have been offered. However, these solutions are often overly complex in manufacture, require retrofit to existing gates, require organized administration of key distribution, are not applicable to chain lock systems, are prone to intentional or accidental disassembly by users, and/or openly expose the separate locks to attack by intruders.
The Multiple Padlock Latch of McNeil (U.S. Pat. No. 6,857,299) includes a door latch that can be pushed open by any one of a series of pins. The pins can each be secured with a separate padlock. To open the latch, a user removes his padlock from one of the pins, allowing the pin to be pushed in to disengage the latch so the door can be opened. However, this system is somewhat complex, is easily damaged, is not easily installed on existing doors, and does not functionally interact with chains common to many gated fences
Sliding bolt latches with multiple locks, such as those of Domes (D267,698), and Eaker (U.S. Pat. No. 5,868,015), have a latch mounting body on a gate with series of sliding link sections mounted to the gate bolt between anchor tabs. A series of padlocks can connect the anchor tabs through the sliding links so that the bolt can not be withdrawn from a receiver, thus preventing the gate from being opened. Removal of any one padlock disconnects the anchor tabs, allowing the bolt to slide from the receiver, so the gate can be opened. Still, these systems can suffer from too open exposure of the locks to intruders, retrofit difficulties, and a lack of ready functional interaction with existing chain systems.
In view of the above, a need remains for a multi-user locking system that is simple yet shielded from attack. It would be desirable to have a multilock system that is compatible with existing chain lock systems and easily retrofitted to common gates. The present invention provides these and other features that will be apparent upon review of the following.